（1）974×74+974+974×25
=974x(74+1+25)   乘法分配律
=974x100
=97400



（2）1.25×67.875+125×6.7875+1250×0.053375
=12.5×6.7875+12.5×67.875+12.5×5.3375
=12.5×(6.7875+67.875+5.3375)    乘法分配律
=12.5x80
=1000




（3）[五十分之一+（2-0.5）÷二十分之三]÷100.2
=(0.02+1.5÷0.15)÷100.2
=10.02÷100.2
=0.1





（4）6.8×6.8+四又五分之一×6.8-6.8
=6.8x6.8+4.2x6.8-1x6.8
=6.8x(6.8+4.2-1)    乘法分配律
=6.8x10
=68